[Mining and analysis of regulatory loci for VB6 content in rice grains]

Vitamin B6 (VB6), as an essential component involved in numerous biological activities of animals and plants, reflects the nutritional quality of cereal crops such as rice. Few studies have been conducted to mine the genes controlling the VB6 content in rice grains, and the available studies remain to be deepened. In this study, the recombinant inbred lines created from parents 'HZ' and 'Nekken2' served as the experimental materials. Based on QTL mapping, the initial screening identified ten candidate genes. The expression levels of LOC_Os01g52450, LOC_Os01g52500, LOC_Os05g09500, LOC_Os05g09440, LOC_Os05g20570, and LOC_Os05g36270 showed significant differences between the parents. According to the gene expression and parental VB6 content, we hypothesized LOC_Os05g09500 as the key gene affecting the VB6 content in rice grains, and the high expression of this gene significantly influenced the VB6 content. The results of this study fill a gap in the QTL mapping on the VB6 content of rice grains and provide theoretical support for elucidating the molecular genetic mechanisms and cloning the related genes of VB6 synthesis in rice. In addition, the findings have significant implications for identifying, screening, and breeding new rice cultivars with high VB6 content.